1. Field of the Invention
This invention relates to a radiometric analyzer for precisely measuring various characteristics of a material, e.g. a hydrocarbon, under rational automatic calibration to the change of formula of the material in an analyzer for measuring various characteristics of the material with radiation.
2. Description of the Prior Art
Analyzers for measuring various characteristics of a material by radiation techniques are known in the art. However, by and large, such analyzers have not measured the precise physical characteristics of the material, but rather have measured approximate values.
In order to measure more precisely the characteristics of a material, it is necessary to compensate the measured values depending upon the change of formula of the material. The compensation of the formulation of a material may be, for example, a compensation by the ratio of carbon to hydrogen for a measurement of the density of a hydrocarbon. In order to measure the density of a hydrocarbon, the number of atoms of carbon and hydrogen in a unit of volume are respectively multiplied by a weighing factor which is the ratio of the mass numbers (12 : 1) and are then added together. However, when a .gamma.-ray density meter is used, the weighing factor is not the ratio of the mass numbers, but is approximately the ratio of the atomic numbers (6 : 1), so that the correspondence of the measured value of the density will not be accurate.
Heretofore, as a compensation of the measured values, the hydrogen density and the ratio of carbon to hydrogen atoms have been separately measured and the compensation has been introduced by a desirable calibration coefficient as a result of experiments. However, it has been difficult to determine precisely the compensation function required by such conventional methods due to requirements of greater accuracy.
Additionally, when multiple compensations are yielded by using parallel systems for detection, the calibrations are very complicated so as to make it difficult to determine the required operations including the relationships of the response functions of each detective system in automatic operations. Also, the physical meaning of the operated output becomes unclear and a presumption of residual error exists.